US11703385B1 - Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor - Google Patents

Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor Download PDF

Info

Publication number
US11703385B1
US11703385B1 US17/952,142 US202217952142A US11703385B1 US 11703385 B1 US11703385 B1 US 11703385B1 US 202217952142 A US202217952142 A US 202217952142A US 11703385 B1 US11703385 B1 US 11703385B1
Authority
US
United States
Prior art keywords
capacitor
switch
voltage
switching unit
light sensor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US17/952,142
Inventor
Wen-Sheng Lin
Sheng-Cheng LEE
Yueh-Hung Ho
Chih-Wei Lin
Chen-Hua Hsi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Luxsentek Microelectronics Corp
Original Assignee
Luxsentek Microelectronics Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Luxsentek Microelectronics Corp filed Critical Luxsentek Microelectronics Corp
Assigned to LUXSENTEK MICROELECTRONICS CORP. reassignment LUXSENTEK MICROELECTRONICS CORP. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HO, YUEH-HUNG, HSI, CHEN-HUA, LEE, SHENG-CHENG, LIN, CHIH-WEI, LIN, WEN-SHENG
Application granted granted Critical
Publication of US11703385B1 publication Critical patent/US11703385B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/4228—Photometry, e.g. photographic exposure meter using electric radiation detectors arrangements with two or more detectors, e.g. for sensitivity compensation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
    • G01J1/16—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors
    • G01J1/1626—Arrangements with two photodetectors, the signals of which are compared
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/4204—Photometry, e.g. photographic exposure meter using electric radiation detectors with determination of ambient light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/44—Electric circuits
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/44—Electric circuits
    • G01J1/46—Electric circuits using a capacitor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/44—Electric circuits
    • G01J2001/444—Compensating; Calibrating, e.g. dark current, temperature drift, noise reduction or baseline correction; Adjusting

Definitions

  • the present invention relates to a light sensor and that is characterized by the circuit of dark current elimination.
  • Light sensors generally use photodiodes to sense optical signals and convert them into electrical signals.
  • the photodiode mixes a sensed current and a thermal leakage that is also called dark current.
  • the dark current grows almost exponentially and the sensed current is smaller and that impacts seriously the sensor.
  • the present invention proposes a circuit, embedded in the sensor, and that is fast, efficient and sensitive in elimination of dark current.
  • the present invention provides a light sensor with dark current elimination, comprising:
  • FIG. 1 is a circuit configuration diagram of a light sensor of the present invention.
  • FIG. 2 is an operation timing diagram of the light sensor of FIG. 1 .
  • a dark current measuring unit uses a photo sensor, avoiding exposed to the light to generate dark current.
  • An ambient light sensing unit uses a photo sensor, illuminated by ambient light to generate a sensing current.
  • the photosensors can be photodiodes and the photodiodes have the same or similar photoelectric properties. For example, both have the same sensing area to generate the same or similar dark current.
  • Integrating circuits to convert current into voltage, are used.
  • One circuit convert the dark current to a dark voltage, and another covert the sensing current to a sensing voltage.
  • a deduction circuit is proposed, and the circuit can deduct the dark voltage from the sensing voltage and the final output voltage is the lux voltage.
  • the integrating circuit is a switch-capacitor circuit, the capacitor is used to accumulate the current to get a voltage and a switch is used to reset the capacitor, i.e. to release accumulated charge of the capacitor.
  • the first switch-capacitor circuit generates the dark voltage and the second switch-capacitor circuit generates the sensing voltage.
  • a reverse capacitor is disposed between the first switch-capacitor circuit and the second switch-capacitor circuit. The reverse capacitor inverts the voltage phase so the sensing voltage deduct the dark voltage from the sensing voltage to obtain the lux voltage.
  • the reverse capacitor means its positive electrode connected to first switch-capacitor circuit and cathode to the second switch-capacitor circuit.
  • the capacitance of the reverse capacitor determines the measurement sensitivity and efficiency.
  • a small capacitor is used for speeding the measurement.
  • the sensor can measure the lux voltage within 1 ⁇ 2 ms in low illumination environment. In addition, it prevents the switch-capacitor circuit from saturation to reset/discharge the capacitor for keep the function. It determines efficiency of the sensor by controlling the switches.
  • FIG. 1 shows a circuit architecture diagram of the light sensor of the present invention.
  • the sensor comprises a first photodiode 3 , a first switch-capacitor circuit 1 (Switch-Cap Circuit), a second photodiode 4 , a second photodiode, a second switch-capacitor circuits 2 , a reverse capacitor 301 , an analog-to-digital converter 5 , a micro-processing unit 6 and an oscillator 7 .
  • the first photodiode 3 is not exposed to ambient light to generate the thermal leakage, i.e. the dark current (I dark ).
  • the second photodiode 4 is irradiated by the ambient light to generate a sensing current (I light ), which includes a photocurrent (I lux ) and a dark current (I dark ).
  • the first capacitor 101 of the first switch-capacitor circuit can accumulate the dak current to generate the dark voltage, V D_OUT .
  • the third switching unit SW3 can reset the switch-capacitor circuit.
  • the first amplifier 102 can avoid reverse current by keeping the ground reference voltage.
  • the first photodiode 3 is connected to the first switch-capacitor circuit via the first switching unit SW1. The saturation of the capacitor 101 can be avoided by controlling the switching of the third switching unit SW3.
  • the second switch-capacitor circuit 2 can convert the sensing current (I light ) into a sensing voltage, V light .
  • the second switch-capacitor circuit 2 has the same structure and function as the first switch-capacitor circuit 1 , and includes a second capacitor 201 , a fourth switching unit SW4 and a second amplifier 202 .
  • the positive electrode and the negative electrode of the reverse capacitor are connected to the first switch-capacitor circuit 1 and the second switch-capacitor circuit 2 , respectively.
  • the reverse capacitor can invert the dark voltage to the second switch-capacitor circuit 2 , and reduced the voltage from the sensing voltage.
  • the second switch-capacitor circuit 2 directly exports V OUT , that is the lux voltage.
  • V D_OUT I dark *( T int /C int ) (1)
  • V light ( I lux +I dark )*( T int /C int ) (2)
  • V OUT Puc *( V light ⁇ ( C iv /C int )* V D_OUT ) (3)
  • T int and C int are the accumulation (integration) time and capacitance, respectively, which are positively correlated with the pulse length Puw, C iv is the reverse capacitance, and Puc is the number of pulses.
  • C iv /C int 1
  • V OUT V light ⁇ V D_OUT .
  • the digital signal is input to the micro-processing unit 6 as the controlling parameters of the switching units including SW1, SW2, SW3 and SW4.
  • the oscillator 7 generates the stable pulses and is employed as clock of the micro-processing unit 6 .
  • the time frame is shown as FIG. 2 , and the detail is as below.
  • the first switching unit SW1 and the second switching unit SW2 are synchronized and it means the dark currents of the photodiodes 3 and 4 are also synchronized.
  • the first switch-capacitor circuit 1 is configured to generate the correct dark voltage quickly.
  • the first capacitor 101 can accumulate the current quickly to generate the first voltage V D_OUT and be refreshed to avoid saturation, so the third switching unit SW3 resets the first capacitor 101 for each switching period.
  • the second switch-capacitor circuit 2 is configured to generate and enhance the lux sensing signal, so the second capacitor 201 can accumulate the small lux current for a longer period. The faster and more efficient if the second capacitor 201 is smaller the value. But if the second capacitor 201 is too small, the saturation occurs. The second capacitor 201 is refreshed about few cycles and it will not be saturated in the accumulation period. In this embodiment, the saturation time of the second capacitor 201 is 3 cycles.
  • the first capacitor 101 and the second capacitor 201 have the same capacitance value and are saturated in about 3-5 cycles.
  • the first switching unit SW1 and the second switching unit SW2 are synchronized to ensure that the first capacitor 101 and the second capacitor 201 have the same dark currents (dark voltage).
  • the SW3 is ON for discharging in the OFF of the SW1(the SW2 is also OFF). In the ON state of the SW1, the SW3 is OFF for accumulation of the dark current.
  • the SW3 is out-phase to the SW1 and the SW2.
  • the SW4 is turned on to initialize the measurement at first switching period and then turned off to start to accumulate the lux current.
  • the capacitor 201 will be saturated after 3 to 5 pulse periods to complete the sensing.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Light Receiving Elements (AREA)

Abstract

The present invention provides a light sensor with dark current elimination. A dark current from a covered photodiode and a sensed current from a photodiode are respectively transformed to a dark voltage and a sensed voltage by a controlled integration circuit. A reverse capacitor receives the dark voltage and the sensed voltage to cancel out for each other, and outputs a corrected sensing voltage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a light sensor and that is characterized by the circuit of dark current elimination.
2. Description of the Prior Art
Light sensors generally use photodiodes to sense optical signals and convert them into electrical signals. Usually, the photodiode mixes a sensed current and a thermal leakage that is also called dark current. In the environment of high temperature and low illumination, such as the sensor under the display screen of the mobile phone, the dark current grows almost exponentially and the sensed current is smaller and that impacts seriously the sensor.
In convention, it is inefficient to eliminate the dark current generally. The present invention proposes a circuit, embedded in the sensor, and that is fast, efficient and sensitive in elimination of dark current.
SUMMARY OF THE INVENTION
In order to solve the above problems, the present invention provides a light sensor with dark current elimination, comprising:
    • a first switch-capacitor circuit to convert a dark current of a first photodiode, without being exposed to ambient light, into a first voltage;
    • a second switch-capacitor circuit to convert a sensing current of a second photodiode, with being exposed to the ambient light, into a second voltage; and
    • a reverse capacitor connected between the first switch-capacitor circuit and the second switch-capacitor circuit, to deduct the second voltage from the first voltage and then to generate an output voltage (VOUT).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit configuration diagram of a light sensor of the present invention.
FIG. 2 is an operation timing diagram of the light sensor of FIG. 1 .
 DESCRIPTION OF THE PREFERRED EMBODIMENTS
Below embodiments accompanied with drawings are used to explain the spirit of this invention to have better understanding for the person in this art, not used to limit the scope of this invention, which is defined by the claims. The applicant emphasizes the element quantity and size are schematic only. Moreover, some parts might be omitted to skeletally represent this invention for conciseness.
A dark current measuring unit uses a photo sensor, avoiding exposed to the light to generate dark current. An ambient light sensing unit uses a photo sensor, illuminated by ambient light to generate a sensing current. The photosensors can be photodiodes and the photodiodes have the same or similar photoelectric properties. For example, both have the same sensing area to generate the same or similar dark current.
Integrating circuits, to convert current into voltage, are used. One circuit convert the dark current to a dark voltage, and another covert the sensing current to a sensing voltage. A deduction circuit is proposed, and the circuit can deduct the dark voltage from the sensing voltage and the final output voltage is the lux voltage.
The integrating circuit is a switch-capacitor circuit, the capacitor is used to accumulate the current to get a voltage and a switch is used to reset the capacitor, i.e. to release accumulated charge of the capacitor. The first switch-capacitor circuit generates the dark voltage and the second switch-capacitor circuit generates the sensing voltage. A reverse capacitor is disposed between the first switch-capacitor circuit and the second switch-capacitor circuit. The reverse capacitor inverts the voltage phase so the sensing voltage deduct the dark voltage from the sensing voltage to obtain the lux voltage. The reverse capacitor means its positive electrode connected to first switch-capacitor circuit and cathode to the second switch-capacitor circuit.
The capacitance of the reverse capacitor determines the measurement sensitivity and efficiency. A small capacitor is used for speeding the measurement. The sensor can measure the lux voltage within 1˜2 ms in low illumination environment. In addition, it prevents the switch-capacitor circuit from saturation to reset/discharge the capacitor for keep the function. It determines efficiency of the sensor by controlling the switches.
FIG. 1 shows a circuit architecture diagram of the light sensor of the present invention. The sensor comprises a first photodiode 3, a first switch-capacitor circuit 1 (Switch-Cap Circuit), a second photodiode 4, a second photodiode, a second switch-capacitor circuits 2, a reverse capacitor 301, an analog-to-digital converter 5, a micro-processing unit 6 and an oscillator 7.
The first photodiode 3 is not exposed to ambient light to generate the thermal leakage, i.e. the dark current (Idark). The second photodiode 4 is irradiated by the ambient light to generate a sensing current (Ilight), which includes a photocurrent (Ilux) and a dark current (Idark).
The first capacitor 101 of the first switch-capacitor circuit can accumulate the dak current to generate the dark voltage, VD_OUT. The third switching unit SW3 can reset the switch-capacitor circuit. The first amplifier 102 can avoid reverse current by keeping the ground reference voltage. The first photodiode 3 is connected to the first switch-capacitor circuit via the first switching unit SW1. The saturation of the capacitor 101 can be avoided by controlling the switching of the third switching unit SW3.
The second switch-capacitor circuit 2 can convert the sensing current (Ilight) into a sensing voltage, Vlight. The second switch-capacitor circuit 2 has the same structure and function as the first switch-capacitor circuit 1, and includes a second capacitor 201, a fourth switching unit SW4 and a second amplifier 202.
The positive electrode and the negative electrode of the reverse capacitor are connected to the first switch-capacitor circuit 1 and the second switch-capacitor circuit 2, respectively. The reverse capacitor can invert the dark voltage to the second switch-capacitor circuit 2, and reduced the voltage from the sensing voltage. As a result, the second switch-capacitor circuit 2 directly exports VOUT, that is the lux voltage.
The formula for converting current to voltage is as follows:
V D_OUT =I dark*(T int /C int)  (1)
V light=(I lux +I dark)*(T int /C int)  (2)
V OUT =Puc*(V light−(C iv /C int)*V D_OUT)  (3)
Tint and Cint are the accumulation (integration) time and capacitance, respectively, which are positively correlated with the pulse length Puw, Civ is the reverse capacitance, and Puc is the number of pulses. For simplifying the calculation, let Civ/Cint=1, and VOUT=Vlight−VD_OUT.
Next, it is to convert the output voltage VOUT into a digital signal by the ADC 5. The digital signal is input to the micro-processing unit 6 as the controlling parameters of the switching units including SW1, SW2, SW3 and SW4. The oscillator 7 generates the stable pulses and is employed as clock of the micro-processing unit 6.
It can eliminate the thermal disturbance, i.e. dark current, from the sensing signal by coordinating these switching units, the time frame is shown as FIG. 2 , and the detail is as below.
The first switching unit SW1 and the second switching unit SW2 are synchronized and it means the dark currents of the photodiodes 3 and 4 are also synchronized.
The first switch-capacitor circuit 1 is configured to generate the correct dark voltage quickly. The first capacitor 101 can accumulate the current quickly to generate the first voltage VD_OUT and be refreshed to avoid saturation, so the third switching unit SW3 resets the first capacitor 101 for each switching period.
The second switch-capacitor circuit 2 is configured to generate and enhance the lux sensing signal, so the second capacitor 201 can accumulate the small lux current for a longer period. The faster and more efficient if the second capacitor 201 is smaller the value. But if the second capacitor 201 is too small, the saturation occurs. The second capacitor 201 is refreshed about few cycles and it will not be saturated in the accumulation period. In this embodiment, the saturation time of the second capacitor 201 is 3 cycles.
Generally, in order to simplify the calculation, the first capacitor 101 and the second capacitor 201 have the same capacitance value and are saturated in about 3-5 cycles.
The first switching unit SW1 and the second switching unit SW2 are synchronized to ensure that the first capacitor 101 and the second capacitor 201 have the same dark currents (dark voltage).
The SW3 is ON for discharging in the OFF of the SW1(the SW2 is also OFF). In the ON state of the SW1, the SW3 is OFF for accumulation of the dark current. The SW3 is out-phase to the SW1 and the SW2. The SW4 is turned on to initialize the measurement at first switching period and then turned off to start to accumulate the lux current. The capacitor 201 will be saturated after 3 to 5 pulse periods to complete the sensing.
The output voltage VOUT is the sensing voltage reduced by VD_OUT through the reverse capacitor 301 as the following calculation:
V OUT −V light −V D_OUT =V lux +V D_OUT −V D_OUT =V lux  (4)

Claims (6)

What is claimed is:
1. A light sensor with dark current elimination, comprising:
a first switch-capacitor circuit for converting a dark current of a first photodiode, without being exposed to ambient light, into a first voltage;
a second switch-capacitor circuit for converting a sensing current of a second photodiode, with being exposed to the ambient light, into a second voltage; and
a reverse capacitor connected to a first switch-capacitor circuit and the second switch-capacitor circuit, wherein the reverse capacitor inverts the first voltage to deduct the first voltage from the second voltage, and generates an output voltage (VOUT).
2. The light sensor according to claim 1, further comprising:
a first switching unit to switch the first photodiode;
a second switching unit to switch the second photodiode; and
a micro-processing unit, wherein a first switching unit and the second switching unit is controlled by the micro-processing unit which receives the output of the second switch-capacitor circuit via an analog-to-digital converter.
3. The light sensor according to claim 2, wherein
the first switch-capacitor circuit includes a first amplifier, a third switching unit and a first capacitor; and
the second switch-capacitor circuit includes a second amplifier, a fourth switching unit and a second capacitor, wherein the third switching unit and the fourth switching unit is controlled by the micro-processing unit.
4. The light sensor according to claim 3, wherein the third switching unit resets the first voltage for each switching period, and the fourth switching unit resets the output voltage for 3˜5 switching periods.
5. The light sensor according to claim 3, wherein the third switching unit are out-phase to the first switching unit and the second switching unit.
6. The light sensor according to claim 1, wherein the first photodiode and the second photodiode have the same sensing area.
US17/952,142 2022-05-31 2022-09-23 Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor Active US11703385B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
TW111120173 2022-05-31
TW111120173A TW202349935A (en) 2022-05-31 2022-05-31 Light sensor with dark current elimination

Publications (1)

Publication Number Publication Date
US11703385B1 true US11703385B1 (en) 2023-07-18

Family

ID=87163344

Family Applications (1)

Application Number Title Priority Date Filing Date
US17/952,142 Active US11703385B1 (en) 2022-05-31 2022-09-23 Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor

Country Status (3)

Country Link
US (1) US11703385B1 (en)
CN (1) CN117191188A (en)
TW (1) TW202349935A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160377483A1 (en) * 2014-03-17 2016-12-29 Ani.Co.Ltd Color difference meter module capable of performing real-time zero point adjustment and color measuring device using same
US11415459B2 (en) * 2020-12-24 2022-08-16 Luxsentek Microelectronics Corp. Photosensor device with dark current cancellation

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160377483A1 (en) * 2014-03-17 2016-12-29 Ani.Co.Ltd Color difference meter module capable of performing real-time zero point adjustment and color measuring device using same
US11415459B2 (en) * 2020-12-24 2022-08-16 Luxsentek Microelectronics Corp. Photosensor device with dark current cancellation

Also Published As

Publication number Publication date
CN117191188A (en) 2023-12-08
TW202349935A (en) 2023-12-16

Similar Documents

Publication Publication Date Title
JP4929060B2 (en) Analog / digital converter, illuminance sensor, lighting device, electronic equipment
US7071456B2 (en) Camera module with ambient light detection
TWI527256B (en) A light detection device and an image display device
US8288703B2 (en) Photodetection device
JP5209066B2 (en) Sensor device and electronic device
US8259061B2 (en) Optical detection device, and image display device
EP1158789B1 (en) Photodetector device
US9893736B2 (en) Analog to digital conversion device, illuminance sensor device, and electronic apparatus comprising the illuminance sensor device
JP2009158569A (en) Photodetection semiconductor device, photodetector, and image display device
JP2009158570A (en) Photodetection semiconductor device, photodetector, and image display device
US20200092504A1 (en) Optical sensor, particularly hybrid analog-digital optical sensor array
WO1998029716A1 (en) Light sensing device
US4847483A (en) Device for measuring light intensity received by a photosensor
US11703385B1 (en) Light sensor with dark current elimination having duo switch-capacitor circuits and a reverse capacitor
KR100550200B1 (en) Light sensing pixel sensor and method
US8772697B2 (en) Photodetector device
CN115002361A (en) Digital integral charge-digital conversion circuit for measuring current or capacitance
US7489351B2 (en) Dynamic range extension for focal plane arrays
KR100906958B1 (en) Method for converting signal by ADCanalogue-digital converter, and Method for measuring light intensity using it or the method, and ambient light sensor
TWI803061B (en) Optical sensing arrangement, ambient light sensor and method for providing an output count
JPH05244411A (en) Signal converter for photo sensor array
KR20130122212A (en) Ambient light sensor with wide measurement range
JPH05244487A (en) Signal converter for photo sensor array
JP2004072542A (en) Optical sensor
KR20130122204A (en) Ambient light sensor based on haman visual characteristic

Legal Events

Date Code Title Description
FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE